Not really always, because of buoyancy. A balloon of volume V displaces the same amount of air weather it’s filled with air or lead, but in the former case the force is significant.
Comment on Anon is a physicist
jonwyattphillips@lemmy.ml 8 months ago
This is true on earth. If you have objects of the same shape and different weights and you drop them from high enough to reach terminal velocity, the heavier one will have a high terminal velocity through air and reach the ground faster.
The “in a vacuum” thing is where this goes wrong, but I don’t think homeboy really knew about space or vacuums.
observantTrapezium@lemmy.ca 8 months ago
Sprawlie@lemmy.world 8 months ago
no. Gravity is consistently pulling at 9.85m/s regardless of the size or density in an object.
Terminal velocity is reference to the air resistance and buoyancy affect on an object in freefall. This has nothing to do with the mass or size of the object, but it’s air resistance.
openstax.org/books/…/2-7-falling-objects
Gravity is (mostly) consistent across the planet and will always pull the same force regardless of the object in question.
Sludgeyy@lemmy.world 8 months ago
Any object with mass has gravity
Say the moon was falling to earth
Would the earth not be drawn in space towards the moon as it fell?
The moon and earth would collide at a rate faster than 9.85m/s?
Sprawlie@lemmy.world 8 months ago
They actually are. The Moon technically doesn’t orbit the earth, but a point near earth, that earth does as well. Its momentum that prevents the moon from crashing to earth, and it’s gravity that prevents it from flying off into space.
And another interesting fact: The moon’s momentum is slightly greater than that of the earth’s gravity, causing the moon to very very slowly move further away from Earth (About 3.7cm a year).
but it’s these momentums and gravitational forces that keep the moon orbiting (Orbital mechanics is fucking fascinating as fuck)
But what would happen if two bodies collided that are large? The force of impact would be the combined momentum of the two items as you believe. It is believed this is what actually formed our moon as early formation of the planets saw two planet sized bodies impact like you describe, the resulting force spun enough matter to form the moon (Mineral inspection of moon rock shows it contains the same isotopes as earth, which is rare if the moon formed on it’s own).
jonwyattphillips@lemmy.ml 8 months ago
…stackexchange.com/…/terminal-velocity-of-two-equ…
Sprawlie@lemmy.world 8 months ago
You did a google search and just pasted the top link? which is a question about calculating the drag on a falling object.
But you clearly didn’t read the responses, which the first once directly states that the original question misses the premise that it is drag on an object from the atmosphere which causes the affect of different speed. This is the same arugment you made about terminal velocity. It’s the same point. Terminal velocity and the speed slow down of two different objects is still directly related to the atmosphere and it’s affect on an object.
While this is true, We circle back to the fact Terminal Velocity isn’t a measure or an affect of mavity but atmospheric influence on the falling object.
Earth Gravity is consistently pulling on the objects of difference mass at the same velocity. given zero resistances, both would hit the same speed.